Progestational danger sign: 1. With before second childbirth interval resents 4 years; 2. Pregnant woman age is less than 20 years old or be more than 35 years old of;3. Pregnant woman is borne toward what had had for many times already history;4. Had borne before pregnant woman be born weight the child; under 2 kilograms5. Pregnant woman ever had had difficult labor or Caesarean birth history;6. Pregnant woman has had abortion or stillborn foetus, stillbirth history before; 7. Pregnant woman is in weight before be pregnant under 38 kilograms; 8. Pregnant woman height under 145 centimeters;